How do you set up a basic SignalR Hub in an ASP.NET Core application?

Question

Utpal Vishwas · Answer

1. Create a new ASP.NET Core project
You can start with an empty Web API or Web app project.
2. Add the SignalR package
If you don’t already have it, add the SignalR NuGet package:
dotnet add package Microsoft.AspNetCore.SignalR
3. Create a SignalR Hub class
A Hub is a central class where clients and server communicate.
Create a new class like this:
using Microsoft.AspNetCore.SignalR;
using System.Threading.Tasks;
public class ChatHub : Hub
{
    public async Task SendMessage(string user, string message)
    {
        // Broadcast the message to all connected clients
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}
4. Configure SignalR in Startup (Program.cs for .NET 6+)
In ASP.NET Core 6 or later, Program.cs will look something like this:
var builder = WebApplication.CreateBuilder(args);
// Add SignalR services
builder.Services.AddSignalR();
var app = builder.Build();
// Map your hub endpoint
app.MapHubandlt;ChatHubandgt;("/chatHub");
app.Run();
For ASP.NET Core 3.1 or 5, you add SignalR in Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
    services.AddSignalR();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseRouting();
    app.UseEndpoints(endpoints =andgt;
    {
        endpoints.MapHubandlt;ChatHubandgt;("/chatHub");
    });
}
5. Client-side setup
You can use JavaScript to connect to the SignalR hub. Include the SignalR client library (from CDN or npm):
andlt;script src="https://cdnjs.cloudflare.com/ajax/libs/microsoft-signalr/7.0.7/signalr.min.js"andgt;andlt;/scriptandgt;
andlt;scriptandgt;
    const connection = new signalR.HubConnectionBuilder()
        .withUrl("/chatHub")
        .build();
    // Receive message from server
    connection.on("ReceiveMessage", (user, message) =andgt; {
        console.log(`${user}: ${message}`);
        // You can update the DOM here to show the message
    });
    connection.start().catch(err =andgt; console.error(err.toString()));
    // Example of sending a message to the hub
    function sendMessage() {
        const user = "User1";
        const message = "Hello SignalR!";
        connection.invoke("SendMessage", user, message)
            .catch(err =andgt; console.error(err.toString()));
    }
andlt;/scriptandgt;
Summary
Step
What to do
1. Add SignalR package
Add Microsoft.AspNetCore.SignalR
2. Create Hub class
Define methods clients call
3. Register SignalR
In Program.cs or Startup.cs add SignalR and map hub route
4. Client connect
Use SignalR JS client to connect and call hub methods
and

interview

How do you set up a basic SignalR Hub in an ASP.NET Core application?

Utpal Vishwas

Can you answer this question?

1 Answers

1. Create a new ASP.NET Core project

2. Add the SignalR package

3. Create a SignalR Hub class

4. Configure SignalR in Startup (`Program.cs` for .NET 6+)

5. Client-side setup

Summary

Liked By

Step	What to do
1. Add SignalR package	Add `Microsoft.AspNetCore.SignalR`
2. Create Hub class	Define methods clients call
3. Register SignalR	In `Program.cs` or `Startup.cs` add SignalR and map hub route
4. Client connect	Use SignalR JS client to connect and call hub methods